Nokian WR SUV 4 is a winter tyre made in total of 69 sizes, ranging from R16 to R16 - this particular dimension is R20, which means it fits to a 20 inch/508mm diameter wheel. 235/55 R20 is 20mm wider than the narrowest dimension (215) and 80mm narrower than the widest one (315). This tyre profile of 55 means the sidewall height of the tyre is 55% of the tyre width (235mm), which results in 129.25mm sidewall height.
Winter
